what has to be done to swap a c3116 to a c3126

[adaptivehumanity]

I have spent days scouring the internet for answers yet have found nothing, I am looking to swap a 3126 into a A0 that has a 3116 in it. What is needed to do the swap? Reason for it is I have a fresh rebuilt 3126 sitting here with ECU attached.

 

[Guruman]

I thought about doing the same thing only with a C7.

 

[coachgeo]

unless you happen to have the 3126 already via a great deal.... I would not bother with the effort IMHO.

With all it would take...... which is not horrible from what I've read... I'd use the same effort to put in a much better engine.. Esp. if you got killer deal on the 3126.... sell it at fair price the like mentioned add some funds to get a C7.. or less costly yet a better engine..... find a Cummins.

otherwise from what Ive read 3126 will bolt in....you just got to finnagle where to pick up signals that the TCU needs and the 3126's ECU

 

[Skyhawk13205]

The adapter plate in the bell housing is different. Digital throttle, 1939 data bus wiring. I think the physical install would be the easiest part. Hard part is redoing the wiring.

was the 3126 from another FMTV?

 

[Ronmar]

You may need to re-program the transmission to use the TPS info from the data bus... Once you get the throttle by wire all installed and worked out…

 

[fuzzytoaster]

The adapter plate in the bell housing is different. Digital throttle, 1939 data bus wiring. I think the physical install would be the easiest part. Hard part is redoing the wiring.

This right here. It's simply not worth it unless you've got plenty of free time and know how. If your truck has a WTECII transmission it may not be natively-programmable to handle a 3126 as the A1 trucks rolled out the door with WTECIII systems in place. It's a generational thing you'll be pioneering on your own. The cab harness, PDP board, and some of the dash instrumentation are different. You may as well sell the 1078 you have and buy a M1078A1. If you want a clean A1 with a bad engine there's one on facebook for $7500.

 

[S4ndm4nn]

I swapped out the CAT 3116 for a 2006 CAT C7 330HP on my LMTV A0.

The physical installation was relatively easy. However, all the wiring was relatively complicated.

With the C7, the A0 drives very very nice and the fuel consumption is also lower.

If you have any special questions then feel free to ask

 

[adaptivehumanity]

The adapter plate in the bell housing is different. Digital throttle, 1939 data bus wiring. I think the physical install would be the easiest part. Hard part is redoing the wiring.

was the 3126 from another FMTV?

The 3126 was from a wrecked m1078a1. Unfortunately all I have its the engine, engine harness and ECU.

 

[adaptivehumanity]

I swapped out the CAT 3116 for a 2006 CAT C7 330HP on my LMTV A0.

The physical installation was relatively easy. However, all the wiring was relatively complicated.

With the C7, the A0 drives very very nice and the fuel consumption is also lower.

If you have any special questions then feel free to ask

View attachment 865730View attachment 865731View attachment 865732View attachment 865733View attachment 865734

Wow, That dash is awesome. where did you get the wiring from? Was there and issue with the transmission?

 

[S4ndm4nn]

I did all the wiring myself, if you take both schematics of A1 and A0 then it actually goes without major problems.

My LMTV fortunately already had a WTEC III so it was quite easy to connect the TPS via J1939.

The Dash is basically a standard J1939 engine monitor with a customized software.

 

[adaptivehumanity]

I did all the wiring myself, if you take both schematics of A1 and A0 then it actually goes without major problems.

My LMTV fortunately already had a WTEC III so it was quite easy to connect the TPS via J1939.

The Dash is basically a standard J1939 engine monitor with a customized software. View attachment 865739

did you have a donor vehicle? if not where did you source your wire harness and sensor parts? I just have the 3126 engine with engine harness and ECU. So I will need everything else.

 

[S4ndm4nn]

I also had the same conditions
I had a engine with the wiring harness and a gas pedal.
The rest I did myself
So such things as the converting the intercooler from one to two ports , the fuel lines, exhaust system and so on.
All you need for the wiring are standard parts the wiring diagrams and a lot of patience

So I would not recommend you to do this especially if you live in the USA and you can get a non running A1 for relatively small money.

 

[adaptivehumanity]

I did all the wiring myself, if you take both schematics of A1 and A0 then it actually goes without major problems.

My LMTV fortunately already had a WTEC III so it was quite easy to connect the TPS via J1939.

The Dash is basically a standard J1939 engine monitor with a customized software. View attachment 865739

Did you swap your doors out? or are those just inner panels?

 

[S4ndm4nn]

Did you swap your doors out? or are those just inner panels?

yes i changed the doors to MAN L2000 doors

 

[coachgeo]

yes i changed the doors to MAN L2000 doorsView attachment 865858

Id heard recently about somethings from L2000 cab would swap over.....hmmm niceeeee.

look forward to a write up and pics on what it took to do it.

what Continental's you running?

actually.... so we dont hijack this guys thread.... please do a separate few write up of you mods, build, tires, doors lol..... ok... that's a lot... take your time but please do..... or post links to a german site where you have already done this and we can try to use web translation to read it

 

[GeneralDisorder]

Sell both and buy a C7 truck?

 

[Third From Texas]

Sell both and buy a C7 truck?

Pass me some of that Grey Poupon, old chap!

Heh, it's a pretty exclusive club still.

 

[GeneralDisorder]

Pass me some of that Grey Poupon, old chap!

Heh, it's a pretty exclusive club still.

True. The research I did prior to purchase and waiting till the right one came along...... played heavily into my purchase. Even still my truck has it's share of issues that I'm still working out.

I love the guys that want the 3116 trucks because they are "mechanical!" - entirely overlooking the electronically controlled transmission with the older WTECII module being significantly less reliable overall than either the 3126b or the C7 engine computer and the later transmission modules being much better so overall the A1 and later trucks have significantly improved reliability - the military even tested and published those results.

 

[B-Dog]

I love the guys that want the 3116 trucks because they are "mechanical!"

And, without a doubt, I would do it all again and again

I have an A0 and an A1. Guess which one ran fine one day, sat for a month and I haven't been able to get running again since then. I will admit, I haven't spent a lot of time troubleshooting but I've spent enough to know that the problem is something electronic and given the choice, I'd choose the A0.

 

[GeneralDisorder]

And, without a doubt, I would do it all again and again

I have an A0 and an A1. Guess which one ran fine one day, sat for a month and I haven't been able to get running again since then. I will admit, I haven't spent a lot of time troubleshooting but I've spent enough to know that the problem is something electronic and given the choice, I'd choose the A0.

"Electronic" or simply "Electric" ?

Big differences.